The T4x series were somewhat noted for noisy fans. Check your power manager (IBM or Windows or both) and make sure your CPU is set for adaptive (managed) mode. Your CPU should be running about 600 or 800 Mhz most of the time and not flat out. Also install a temperature meter (Mobile Meter). When the CPU goes over about 37 C the fan will go on high. Once cooled down and adaptive, the fan should spin down. Any load will cause it to speed up. Check by putting the laptop on a hard surface (for air flow) and let it idle for 30 minutes.
If after all, it will not spin down, there may be a hardware problem. Also try updating the BIOS before concluding there is a hardware problem. ... Thinkpads_User
